The present invention concerns a camera that projects data on X-ray film. More particularly, the present invention concerns a camera which images data onto x-ray film along a row through an open window in the cassette.
X-ray films are employed in industry to detect defects in materials and in the field of medicine for diagnosis. It is often necessary to record along with the image such associated data as date of exposure, operator's name, type of film, tube voltage, description of subject, etc. Medical applications also require such patient-specific data as name, date of birth, insurance provider, etc. on the film. Patient-specific data can be previously printed or typed on cards as described in the U.S. Pat. No. 4,383,329, with one card for each patient, and thereby projected onto the film. Since, on the other hand, such data are often stored digitally in a central computer, some way of recording them directly on the film is also desirable. The liquid-crystal display described in the U.S. Pat. No. 4,383,329 is not particularly effective for the purpose because such displays still do not provide adequate contrast to ensure satisfactory legibility on film.
Patient-specific data are currently entered in batches into a central computer, either manually through terminals comprising a monitor and keyboard or from patient identification cards, such as those called C2 cards, by magnetic strip or bar code readers. The digitized data can then be processed in accordance with a specific program in the central computer and forwarded to other equipment as desired.
A system for projecting data on X-ray film is also known from the published International Application No. WIPO 89/06377. In this system the data is projected onto the film from light-emitting diodes. The film is accommodated, as is conventional in the medical field, in a cassette. The cassette has a window through which the data can be projected onto the film. The diodes are distributed in a row that moves perpendicularly over the exposure window, and flash sequentially or simultaneously, constructing characters on the film point by point.
The resolution obtainable at a comparable range of contrast with a system like that described in the WIPO document, however, is not as satisfactory as that obtained with the recording apparatus described in the aforesaid U.S. patent.